Don't traverse into .svn directories.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82978 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/lit/lit.py b/utils/lit/lit.py
index f9e75cd..5b24286 100755
--- a/utils/lit/lit.py
+++ b/utils/lit/lit.py
@@ -261,7 +261,7 @@
     # Search subdirectories.
     for filename in os.listdir(source_path):
         # FIXME: This doesn't belong here?
-        if filename == 'Output' or filename in lc.excludes:
+        if filename in ('Output', '.svn') or filename in lc.excludes:
             continue
 
         # Ignore non-directories.